When your dog isn’t acting like themselves—sluggish, not eating, maybe vomiting—it’s easy to assume it’s just a stomach bug or stress. But sometimes, the signs point to something much more serious: Addison’s disease, also known as hypoadrenocorticism.

At the Veterinary Emergency and Specialty Center of Northern Arizona, we often see dogs with Addison’s that go undiagnosed for too long—until a true emergency brings them in. The good news? With timely diagnosis and the right treatment, most dogs with Addison’s go on to live full, happy lives.

This guide will walk you through what Addison’s disease is, how to recognize the symptoms, how it’s treated, and what living with this condition means for your dog—and for you.

What Is Addison’s Disease in Dogs?

Addison’s disease occurs when your dog’s adrenal glands stop producing enough hormones, specifically cortisol and aldosterone. These hormones are critical for:

  • Regulating stress
  • Balancing electrolytes
  • Supporting metabolism and blood pressure

Without them, your dog can become dangerously ill. In fact, an untreated Addisonian crisis is a true medical emergency that requires immediate veterinary care.
 Learn more from Cornell’s Canine Health Center

Causes of Addison’s Disease

1. Autoimmune Disease (Most Common Cause)

In most cases, Addison’s is caused by the immune system mistakenly attacking the adrenal glands. Some breeds—including Standard Poodles, Bearded Collies, and West Highland White Terriers—are genetically predisposed.
 More from Merck Veterinary Manual on causes and types

2. Other Causes

  • Infections or tumors affecting the adrenal glands
  • Trauma
  • Sudden withdrawal from long-term steroid use

Recognizing Symptoms of Addison’s Disease

Addison’s can look like a dozen other things at first—which is why it’s often called “the great imitator.” Knowing the early signs can help you act fast.

Early Signs to Watch For:

Signs of an Addisonian Crisis:

  • Collapse
  • Severe dehydration
  • Low heart rate
  • Shock

These symptoms require immediate emergency care.

Learn how to recognize a pet emergency

How Addison’s Disease Is Diagnosed

1. ACTH Stimulation Test

This is the gold standard for diagnosis. A veterinarian gives a synthetic hormone to test how well the adrenal glands respond. In dogs with Addison’s, cortisol levels will stay low.
 Deep dive: Diagnosing hypoadrenocorticism in dogs

2. Routine Blood Work

Before testing for Addison’s, your vet may notice red flags on basic lab work, such as:

  • Low sodium
  • High potassium
  • Low blood sugar

Learn more:  Why blood work matters for your dog

Treatment Options for Addison’s Disease

Once diagnosed, Addison’s is treatable, but it requires a lifelong commitment to hormone replacement and regular veterinary monitoring.

Hormone Replacement Therapy

  • Glucocorticoids (like prednisone): Replace missing cortisol
  • Mineralocorticoids (like fludrocortisone or injectable Zycortal): Replace aldosterone to regulate electrolyte balance

During a Crisis: Emergency Care

An Addisonian crisis requires:

  • IV fluids
  • Electrolyte correction
  • Steroid injections

 Read more about crisis management

Long-Term Monitoring

  • Regular blood tests
  • Adjusting medication based on your dog’s stress levels, illness, or life changes

Life with a Dog with Addison’s Disease

Daily Care and Routine

Once stabilized, most dogs live normal lives. You’ll just need to:

  • Administer daily or monthly medication (your vet will guide you)
  • Avoid extreme stress when possible
  • Stay consistent with feeding and exercise

Dietary Tips

  • Offer a balanced diet that supports hydration and electrolyte stability
  • Frequent, small meals may help some dogs with energy regulation

Exercise and Stress Management

  • Light to moderate exercise is usually fine
  • Avoid sudden stress or major changes in routine when possible

Why Early Detection Matters

Catching Addison’s early—before a crisis—can be life-saving. If your dog seems off and symptoms aren’t improving with basic treatment, ask your vet about screening for Addison’s. The test is simple, and the benefits of early treatment are enormous.

Let’s Work Together to Keep Your Dog Safe

At the Veterinary Emergency and Specialty Center of Northern Arizona, we understand how overwhelming it can be when your dog isn’t feeling well—and you’re not sure why. If you suspect Addison’s disease or your pet is showing symptoms, don’t wait. Contact us today for guidance or to schedule a diagnostic consultation.

We’re here to help you through the unknown with expert care, empathy, and clear answers.